This paper provides an overview of research developments toward nanometer-scale electronic switching devices for use in building ultra-densely integrated electronic computers. Specifically, two classes of alternatives to the field-effect transistor are considered: 1) quantum-effect and single-electron solid-state devices and 2) molecular electronic devices. A taxonomy of devices in each class is provided, operational principles are described and compared for the various types of devices, and the literature about each is surveyed. This information is presented in nonmathematical terms intended for a general, technically interested readership

During the last decade the field of single electron devices has matured from pure theoretical ideas of elements working at very low temperatures (milli Kelvin range) to fabricated devices operating at room temperature. These ideas are moving now from the experimental physics to the electronic circuits domain. New applications are sought and single electron devices may become a replacement for standard CMOS in several areas. This thesis presents a possible approach to this goal. A brief introduction of the aspects and general problems of current digital logic devices and a detailed background on single electronics theory and applications are presented. The fabrication issues of nanometer scale structures are discussed followed by a brief account on the estimation of electric parameters of such devices. A novel multi-valued adder circuit is introduced, where the emphasis is on its implementation for decimal addition. A detailed analysis and simulation results indicating its sensitivity...

Abstract. Single-electron tunneling devices can detect charges much smaller than the charge of an electron. This enables phenomenally precise charge measurements and it has been suggested that large scale integration of single-electron devices could be used to construct logic circuits with a high device packing density. Here the operation of the two basic types of single-electron tunneling transistors is reviewed. The applications of singleelectron tunneling in precision measurements and in general purpose computation is discussed. Particular attention is paid to the characteristics of single-electron tunneling transistors in the superconducting state.